Congenital or acquired recurvatum genu might be caused by bone and/or soft tissue disorders. In bone recurvation, tibial deformity is more common; femoral deformity has clinical and X-ray features that are less important and often unidentified. We found this type of deformity in only four of 40 cases of bone recurvation.

Bone recurvation can follow a tibial or femoral fracture as well as injury with no X-ray signs. Some months later an anterior epiphysiolisis might be recognised on X-ray. This fact allows a retrospective diagnosis of fifth type Salter-Harris epiphysiolisis. Clinically a harmonious recurvatum genu would be recognised, which is difficult to distinguish from a capsulo-ligamentous disorder.

According to a subjective profile, it is featured with no objective laxity. On X-rays there are no peculiarities in the anterior view, but on the lateral view femoral condylar flattening with anterior rotation, in particular in the lateral one, can be observed. It might be useful to compare the X-ray findings to define a geometrical point termed the femoral diaphysealintercondylar angle. This has been already described and is measured between two lines, one which represents the axes of the femoral shaft, the other one the Blumensaat line; in a normal knee this angle measures 33° (±3). In knees with femoral recurvation this is higher: in our four patients the range of the angle was 45°–58°.

Procurving femoral osteotomy is the gold standard; in fact femoral closed wedge osteotomy allows a complete correction. Surgeons must avoid an overcorrection with subsequent femoral trochlear rotation and at the same time a tibial osteotomy must be avoided, which would lead to a double articular deformity, wherever it would fit with a capsulo-ligamentous recurvation.

Tibial and femoral deformities might cause patellofemoral problems, but they do not have to be modified every time to obtain good results. We have evaluated external tibial rotation characterised by an external tibial deformity in varus, worsening in parallel feet position. In these patients the only surgical treatment is tibial osteotomy, justified by a positive effect on the knee joint mechanics. From 1990 to 2002 we performed 25 derotation tibial osteotomies as an isolated procedure or associated with a closed wedge osteotomy. We reviewed 15 patients (16–28 years old at surgery) with special reference to pain, aesthetic criteria and functional assessments, and we reported possible negative effects of derotation (recurvation and external tibial rotation). In all the patients we found an external rotation higher than standard range and moderate varus. All patients had remission of pain; this was complete in five and partial in six. Ten patients showed an increased tibial rotation and eight of those showed even recurvation without functional sequelae. At 2–12 years of follow-up, our results are satisfactory.

In this work we mean explain our clinical experience about the use of a T.R.K. mobile meniscal bearing implanted during the 2000 and 2001 in our institute. The prostheses design allows the motion of the polietilenic component 5mm in the anteroposterior directions and 12.5 degrees in the internal and external rotation.

In association with the shaping of the femural contact surfaces this design allows a huge upgrade of contact surfaces compared with other protheses already in use. We have evaluated 17 patients on short term follow up, patients operated in our division, four males and 13 females. The average ages are 68 ± 8.

The indication was in all cases gonartrosis. The evaluation protocol includes:

§ Pre and post operative x rays (after 60 days);

§ Clinical evaluation of the range of motion;

§ D.E.X.A. mineralometry;

§ Stabilometric evaluation pre operative and after 6 months.

The first results have pointed out the disappearing of pain in all the patients, an optimal recovering of the articular function with no loss of extension, a good prothesic osteointegration (even in an initial phase in our cases) and the stabilometric evaluation confirms a soon proprioceptivity recovering and the motion of the operated limb.

After all this encouraging results we have decided to continue implanting this kind of protheses as we think that not only it warrants a better range of motion, but the utmost null polietilenic debris may allows a longer life to the implant as a consequence of the reduced stress rate.

Since 1989 more than 5000 Zweymuller stems have been implanted in the Orthopaedic Institute G. Pini, Milan, Italy. This uncemented stem which has been produced since 1979 nowadays is though to be one of the best prothesical solutions and this can be affirmed both on the easy operative techniques and on the bases of our clinical studies of follow up. This is also the most used uncemented coxofemural system in Europe. The advantages in the Zweymuller design are due to the rotatory stability and the slight volume of the implant, which in the international literature are referred as the key points of this success. The bone anchorage and the distribution of the weights is achieved both proximally and distally thanks to the conical stem, which in the proximal region is anchored on one side by the great wing of the trocanteris on the other side by the wedge effect.

In the distant cortical instead the borders of the stem get wedged in the bone. This very wide anchorage allows a great stability reflected also by the lack of weigh pain at diafisys level.

The same stem is used both for first implant as well as revisions (after evaluation of the bone stock, achieved in our studies by dexa) but also for intertrocanteric osteotomies.

The chance of a rapid mobilization of the patient makes this stem convenient also in geriatric orthopaedic cases. The material is a alloy of Ti, Al and Nb: this material has been studied directly for medical appliances and not only it doesn’t contain toxic or allergenic components but provide an high resistence to breaks. Osteointegration is favoured by the rough surfaces.

In our last clinical study on the follow up of patients treated with this kind of implant in the last 18 months we have seen a difference in those cases in which a pneumatic driver for nailing had been used in the operative room. Not only the operative time for the positioning has been reduced of one third but the implant resulted to be more precise.

The use of this driver allows a better fitting of the stem to the femural shaft as the cut is more precise. In fact the surgeon has a controlled magnitude and direction of the driving force and this force is anyway limited.

There is a remarkable reduction of cases of intra operative fractures. So we have collected datas on 70 randomized patients in whom this device had been used compared to the same number of patients operated without this apparel: the operative time is reduced of 15 minutes in average and as a consequence the risk of fat emboly has diminished; revisions for malpositioning and intraoperative fractures are almost worthless. Moreover the blood loss has reduced of 100 cc. This are only partial datas but seem to suggest that this device can provide a great help to the orthopaedic surgeon in the operative room as well as reducing complicances in patients: we plan that this driver together with the Zweymuller stem will represent in the future one of the most safe solution in the total hip replacement when the surgeon puts the indication for an uncemented implant.

The great diffusion of total hip replacement in young patients has generated as a consequence an increasing in the number of prothesic failing associated with more or less extended bone loss. We mean analyze the various surgical solution to this problem. In the planning of the best surgical treatment the evaluation of the degree of osteolysis is the more correct technique; in fact we have supported the classical radiological exams with the miralometry as DEXA (supplying quantitative data on the periprotesic bone stock). Data obtained in this way allow choosing more carefully the best protheses in the preoperative planning: mid or long stem, with or without bone graft, with or without materials which may promote a bone rehabilitation. Anyway the surgeon should have all the possible protheses solutions as it happens to change the operative plan during the operation. These are the criterion of choice of the revision protheses, keepin’ in consideration data acquired by D.E.X.A.:

GIR 1 (loosening and or widing of the femural shaft with reducing of the cortical without interruption of walls): If the mobilized protheses is uncemented and DEXA supplies datas about a good bone stock we try to use a first implant uncemented protheses

Kotz’s design, on the bases of follow up studies, seem to support Wagner’s theories about the distant anchorage: There is an attempt of periprothesic corticalization even though the huge bone loss. In the last years we have performed a revision modular distally anatomic stem characterized by a metafi sarial leaning on the proximal component.

The weight bearing is progressive on the base of the radiological evolution and DEXA as well. The complete bearing will be allowed only after a sufficient bone restoration.

In our experience uncemented protheses in the stem revision can allow in mid and long term good results expecially keeping in consideration that these patients had already coxofemural problems. The range of motion is difficulty improvable so the results must be weighted on the bases of the previous clinical situation. If patients are monitored in order to operate as soon as possible in case of mobilization, the use of uncemented protheses can be a valid way for the functional recovering of these patients.

The pre operative evaluation of the degree of osteolisys in cotyle revision in a prothesis is very important in order to plan the best surgical treatment.

In these cases above the traditional radiological and scintigrafic exams we have achieved a evaluation techniques bases on D.E.X.A. This technique allows obtaining data on the periprotheses bone stock. These are the criterion of choice of the revision protheses, keepin’ in consideration data acquired by D.E.X.A.:

GIR 1 (loosening and acetabular widing with persistence of walls). If the cotyle is uncemented and the biological age of the patient allows, we use to treat with a first implant press fit uncemented cotyle.

Conclusions: As a conclusion we can maintain that these indication may supply satisfactory datas thanks to the deep pre operative evaluation by DEXA. We have to keep in consideration that this pathology must be considered urgent: as soon as the operation is achieved the better bone stock will be available to the surgeon. The use of many kind of uncemented cotyle allows us, today more than ever, to restore the correct center of rotation without the risk of further mobilizations.

The various surgical prosthetic solutions in coxarthrosis on a dysplastic basis were evaluated in a critical way.

In our institute more than 3,750 hip prostheses were implanted from 1994 to 1999, and 366 (9.76%) were used for dysplastic coxarthrosis. This high percentage can be explained by the particular geographical position of our institute that has patients coming from the Lombardia region area where CDH is endemic.

Our evaluations consider the highest number of possible parameters in order to realize which is the most modern and reliable surgical solution. Of course, each case is individual and our advantage is to have a prosthesis that is the most suitable for each patient.

The number and type of prostheses used were: 27 ABG, 35 CONUS, 25 CUSTOM MADE, 7 HN, 5 MALLORY, 35 OMNIFLEX, 3 PARHOFER PLASMAPORE, 4 PERSONALISED CUSTOM MADE, 3 RIPPEN, 18 RMHS, 45 SAMO PG, 130 ZWEYMULLER, 18 P507, 6 OMNIFIT, and 5 GYPSE.

From our unique perspective we can consider that in the last several years the use of a cemented prosthesis is progressively disappearing (less than 13%). The use of a cementless prosthesis in young patients (age range 20 to 65) preserves bone stock during implantation, placement and replacement when necessary. If the patient’s age and general conditions allow, we generally operate both dysplastic hips in one stage.

All cases were evaluated with DEXA, which provides qualitative and quantitative data about the periprosthetic bone stock. Various parameters were studied, including restoration of normal biomechanics, centre of rotation, equalisation of limb-length, the Trendelenburg sign, and nerve complications.